ATHENS, Greece -- Greece's top sprinter Costas Kenteris has missed a scheduled dope test on the eve of the Athens Games, Olympics and Greek officials have said.

Kenteris and female Greek athletics hopeful Katerina Thanou were ordered to appear before a disciplinary hearing on Friday to explain their actions.

But in a bizarre twist, both athletes were hospitalized after a traffic accident late Thursday.

They may not be able to attend the hearing ordered by International Olympic Committee President Jacques Rogge.

Police said the pair were on a motorcycle when the accident occurred and that they had not been seriously hurt, according a report by Reuters news service.

But a senior Greek medical source, who declined to be identified, told Reuters: "The injuries are not just scratches."

The pair will stay in hospital overnight and it is uncertain whether they will compete in the Games even if they are cleared by the disciplinary committee.

"As you will understand their psychological state was not good. It seems that it's not something very serious. Tests are ongoing," athletics federation chief Vassilis Sevastis told reporters outside the hospital.

Rogge set up a three-member disciplinary committee to investigate "the nature and circumstances of an alleged anti-doping rule violation committed by two Greek athletes," the IOC said in a statement.

A Greek team spokesman confirmed that Kenteris and Thanou, the Greek women's 100 meters silver medallist at Sydney, had both missed drugs tests because team managers had allowed them to leave the Olympic Village on Thursday evening.

"It seems he (Kenteris) didn't turn up for a test which, to me, is absolutely stupid," an Olympic official confirmed.

"If he didn't turn up, he's a fool and he deserves to be out."

A missed drugs test is normally treated as a failed test and leads to immediate suspension from competition.

The Greek team said it had made a written appeal to the International Olympic Committee (IOC) to give the two athletes more time to undergo tests.

Greek Olympic team leader Yiannis Papadoyiannakis earlier told state-run NET television that "there was no intention from the Hellenic Olympic Committee to hide anything."

"If there has been some kind of misunderstanding that's something different. Many athletes leave the Olympic village for many reasons, to enjoy themselves."

Athens is the first Olympic Games at which a tough new, unified doping code has been in force.

A ban for Kenteris would be a calamity for Greek hopes after a late spurt of impressive preparation and construction for the Games had silenced critics of Athens' sometimes chaotic build-up.

Greek volunteers at the main complex were visibly distressed by news of the missed test and some were in tears.

Many Greeks had speculated that Kenteris, 31, would be given the high honor of lighting the Olympic flame at Friday's opening ceremony.

A senior official at the world athletics' governing body said there appeared to have been a breakdown in communication in the Greek camp, with team officials failing to tell the athletes that they should be available for testing on Thursday evening.

"According to our information the Greek team leader was informed but not the athletes. To our mind this doesn't constitute a refusal," Istvan Gyulai, secretary-general of the International Association of Athletics Federations (IAAF), said.

Kenteris is the only man to win the Olympic, world and European 200 meter titles.

He first attracted attention in 2000 when he set a national record of 20.25 seconds, improving his time to 20.14 in Sydney then to 20.09 when he became the surprise winner before going on to take the world and then European titles.

In the Olympic final, Kenteris came off the bend a meter behind the leaders but surged over the final 50 meters to win ahead of Briton Darren Campbell with pre-race favorite Ato Boldon of Trinidad in third place.